French centrist presidential candidate Emmanuel Macron and his far-right rival Marine Le Pen traded insults in a heated TV debate ahead of this weekend's runoff elections for the presidency.

Marine Le Pen (L) and Emmanuel Macron.

Far-right candidate Marine Le Pen and centrist Emmanuel Macron clashed over their vision of France's future and ways of handling terrorism in an ill-tempered televised debate on Wednesday ahead of Sunday's run-off vote for the presidency.

The two went into the debate with opinion polls showing Macron, 39, maintaining a strong lead of 20 percentage points over the National Front's Le Pen, 48, in what is widely seen as France's most important election in decades.

TRT World's Simon McGregor-Wood has more on the debate from Paris.

Angry exchanges

For Le Pen, the debate, watched by millions, was a last major chance to persuade voters of the merits of her programme which includes cracking down on illegal immigration and ditching the Euro currency.

In angry exchanges, Le Pen played up Macron's background as a former investment banker and economy minister, painting him as a continuation of the outgoing unpopular Socialist government and a backer of rampant globalisation. He accused her of not offering solutions to problems such as France's chronic unemployment.

But the sharpest exchange was over national security, a sensitive issue in a country where more than 230 people have been killed by militants since 2015.

Le Pen accused Macron of being complacent in confronting the threat of fundamentalism. "You have no plan (on security) but you are indulgent with Islamist fundamentalism," she said.

Macron retorted that terrorism would be his priority if he is elected and accused Le Pen of being simplistic. "What you are proposing is snake oil," he said, referring to her proposals to close France's borders.

"I will lead a fight against terrorism at every level. But what they are wanting, the trap they are holding out for us, is the one that you offer - civil war," he said.

Upwards of 20 million viewers out of an electorate of close to 47 million were expected to tune in to the two-and-a-half hour debate.

"Globalisation gone wild"

The two candidates, seated opposite one another at a table in the television studios, mapped out diametrically opposed visions for France.

Macron calls for liberal reforms to kick start the French economy, while Le Pen rails against the loss of French jobs through off-shoring and would adopt protectionist trade measures.

Le Pen labelled Macron a "smirking banker" and said he represented unfettered globalisation.

"Mr. Macron is the candidate of globalisation gone wild, of Uberisation, of precariousness, of social brutality, of war by everybody against everybody ... of the butchering of France by big economic interests," she said, referring to the gig economy typified by US app-based cab service Uber.

Macron hit back by calling Le Pen a liar, saying she was talking nonsense and that her rhetoric lacked substance.

On unemployment, Macron told Le Pen: "Your strategy is simply to tell a lot of lies and just to say what isn't going right in the country."

Abstainers targeted

Wednesday's event marks the first time a National Front candidate has appeared in a run-off debate - an indication of the degree of acceptance Le Pen has secured for the once-pariah party by softening its image in an attempt to dissociate it from past xenophobic associations.

Macron finished only three points ahead of Le Pen in the first round on April 23, but he is widely expected now to pick up the bulk of votes from the Socialists and the centre-right whose candidates were eliminated.

A Cevipof poll published on the website of Le Monde on Wednesday - one of the last big surveys before Sunday's vote - saw Macron getting 59 percent of votes versus 41 percent for Le Pen. An Ifop-Fiducial poll for Paris Match, CNews and Sud Radio gave Macron a 60-40 lead.

Assuming he wins, one of Macron's immediate tasks will be to build a parliamentary majority in follow-up elections in June.

A poll for Les Echos newspaper by OpinionWay-SLPV Analytics suggested Macron was rising to that challenge, showing his party set to emerge as the largest with between 249 and 286 seats in the 577-seat lower house, while the National Front was tipped to win 15 to 25.